It is now convenient to write down the Minkowski and Abraham energy-momentum tensors \(S_{\mu \nu }^M\)  and \(S_{\mu \nu }^A\)  (cf., for instance, Ref. [1]}). The spatial part of Minkowski's tensor is
\(S_{ik}^{\rm M}= -E_iD_k-H_iB_k+\frac{1}{2}\delta _{ik}({\bf E\cdot D+H\cdot B}), \) 
